I think you’re trying to interpret the story as an entirely fictitious metaphor for the real world. And while not invalid, that’s not the point of this discussuon. In the scope of the lore, Conan did battle a giant spider, which was revered by the people as a deity.

How would you explain it within the scope of the lore to exist? Did this giant spider just simply exist, completely detached from the established god of spiders, including giant ones? There’s nothing supernatural about that to you, in this universe of supernatural occurrences?